Lad in our place left a little while back for a job in his old business. It didn't pan out for him and he's come back through the agency route. He's a good, popular lad and management have agreed to reinstate him as a member of staff as soon as they can once the dust has settled in this current climate.
Nobody has mentioned any other time restrictions to this, but that isn't to say there aren't any...just that I'm not aware of any and my managers are even more useless than I am
Anyway, hope that helps and sincerest commiserations that your circumstances have led you to ask this question.